There is known a technology in which provision is made for a low pressure EGR device that supplies an EGR gas from an EGR passage which connects between an exhaust passage at the downstream side of a turbine of a turbocharger and an intake passage at the upstream side of a compressor of the turbocharger. In such an EGR device, the EGR gas containing a large amount of water vapor passes through the compressor. Then, in cases where the temperature of a wall surface of the intake passage at the downstream side of the compressor is equal to or less than a dew point temperature, the water vapor condenses on the wall surface of the intake passage, thereby generating condensed water. Thus, when the condensed water is generated in this manner, there is a fear that component parts of an intake system may be thereby corroded.
On the other hand, it is also known that provision is made for a bypass passage connecting between an upstream side and a downstream side of a compressor, and a bypass valve for opening and closing the bypass passage, wherein in cases where intake air is at a temperature at which condensed water tends to be generated, the temperature of the intake air is caused to rise by opening the bypass valve thereby to circulate the intake air from the downstream side to the upstream side of the compressor (for example, refer to patent literature 1).